Orally administered drugs are first absorbed through the walls of the small intestine and initially travel through the portal vein to the liver, where they undergo metabolism before reaching the systemic circulation. This is known as the first-pass phenomenon.

Polar compounds are readily excreted

Drugs and their metabolites can exit the body in urine, bile, sweat, saliva, breast milk, and expired air. The most important organ for drug excretion is the

Kidneys

what is glomerular filtration?

As blood flows through the glomerular capillaries, fluids and small molecules—including drugs—are forced through the pores of the capillary wall. This process, called glomerular filtration

MEC

Minimum Effective concentration

the plasma drug level below which therapeutic effects will not occur.

Toxic Concentration

The plasma level at which toxic effects begin

Plateau

Steady State

evenly distributed concentration of a drug, occurs when the administration rate equals the rate of drug elimination.

Half Life

is the time needed for the plasma concentration of a drug to be reduced by 50%.

Loading Dose

to achieve plateau more quickly, an initial large dose may be given. Used for drugs with long half –lives

maintenance dose

plateau maintained via smaller doses given after a loading dose

How long does it usually take for a drug to be eliminated out of the body?